/*
 * $Id: stdio_flush.c,v 1.1.1.1 2004-07-26 16:31:30 obarthel Exp $
 *
 * :ts=4
 *
 * Portable ISO 'C' (1994) runtime library for the Amiga computer
 * Copyright (c) 2002-2004 by Olaf Barthel <olsen@sourcery.han.de>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Neither the name of Olaf Barthel nor the names of contributors
 *     may be used to endorse or promote products derived from this
 *     software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _STDLIB_NULL_POINTER_CHECK_H
#include "stdlib_null_pointer_check.h"
#endif /* _STDLIB_NULL_POINTER_CHECK_H */

/****************************************************************************/

#ifndef _STDIO_HEADERS_H
#include "stdio_headers.h"
#endif /* _STDIO_HEADERS_H */

/****************************************************************************/

/* This is roughly equivalent to fflush(), but returns the last character
   written to the buffer, or EOF if flushing produced an error. The putc()
   macro and the internal __putc() macro need this functionality. This
   function is called only if the last character written to the buffer
   was a line feed, prompting the buffer contents to be flushed. It should
   never be used in place of fflush(). */
int
__flush(FILE *stream)
{
	struct iob * iob = (struct iob *)stream;
	int result = EOF;
	int last_c;

	ENTER();

	SHOWPOINTER(stream);

	assert( stream != NULL );

	#if defined(CHECK_FOR_NULL_POINTERS)
	{
		if(stream == NULL)
		{
			SHOWMSG("invalid stream parameter");

			errno = EFAULT;
			goto out;
		}
	}
	#endif /* CHECK_FOR_NULL_POINTERS */

	if(__check_abort_enabled)
		__check_abort();

	assert( __is_valid_iob(iob) );
	assert( iob->iob_BufferWriteBytes > 0 );
	assert( iob->iob_BufferSize > 0 );

	last_c = iob->iob_Buffer[iob->iob_BufferWriteBytes - 1];

	if(__flush_iob_write_buffer(iob) < 0)
	{
		/* Remove the last character stored in the buffer, which is
		   typically a '\n'. */
		iob->iob_BufferWriteBytes--;
		goto out;
	}

	result = last_c;

 out:

	RETURN(result);
	return(result);
}
